Shares of Apple shot up by more than 22 points on Tuesday following word that billionaire investor Carl Icahn had taken a large position in Apple. At one point during the trading day, shares of Apple reached $494 after starting the day trading at $471.50.

Icahn is, of course, a controversial figure, most recently due to his attempts to take over Dell.

Lastly, and in what is likely a reflection of Icahn's business determination, and admittedly somewhat amusing as well, Icahn's Twitter tagline reads in part: "Some people get rich studying artificial intelligence. Me, I make money studying natural stupidity."

With an estimated net worth that exceeds $20 billion, he clearly walks the walk.